Intermittent feed mechanism for high-inertial load



SeptQ'7, 1965 K. J. J. M GOWAN 3,204,528

' INTERMITTENT FEED MECHANISM FOR HIGH-INERTIAL LOAD Filed Sept. 30,1963 I 3 Sheets-Sheet 1 INVENTOR.

KENNETH J. J. MCGOWAN W/IW ATTORNEYS.

Se t. 7, 1965 K. J. J. M GOWAN 3,204,528

INTERMITTENT FEED MECHANISM FOR HIGH-INERTIAL LOAD 3 Sheets-Sheet 2Filed. Sept. 50, 1963 INVENTOR.

KENNETH J. J. MCGOWAN ATTORNEYS.

Sept. 7, 1965 K. J. J. M GOWAN 3,204,528

INTERMITTENT FEED MECHANISM FOR HIGH-INERTIAL LQAD Filed Sept. 50, 1965V 3 Sheets-Sheet 5 INVENTOR.

KENNETH J. J. McGOWAN ATTORNEYS.

United States Patent 3,204,528 INTERMITTENT FEED MECHANISM FORHIGH-INERTIAL LOAD Kenneth J. J. McGowan, Richmond, Ind., assignor toAvco Corporation, Richmond, Ind., a corporation of Delaware Filed Sept.30, 1963, Ser. No. 312,670 19 Claims. (CI. 89-33) The present inventionrelates to intermittent feed mechanisms, and it provides improvements insuch mechanisms particularly suited to the precise handling andpositioning of high-inertia loads. While the invention is not limited tothe driving of a rotary magazine for an automatic gun, it was createdfor such an application and is described below in such context, forpurposes of illustration and not of limitation.

The primary multiple objects of the invention are to provide .anintermittent feed mechanism having the following attributes:

First, the ability to position, start angular rotation of, accelerate,decelcrate, and re-position a high-inertia load with precision and thatquickness of response which is compatible with the high firing rate ofmodern automatic weapons;

Second, simplicity of parts and capability of rapid disassembly andassembly in the field;

Third, spring power and relatively few moving parts of durable andreliable construction.

For a better understanding of the present invention, together with otherand further objects, advantages and capabilities thereof, reference ismade to the following description of the appended drawings in which:

FIG. 1 is a perspective drawing of the several parts of my improvedintermittent feed mechanism, as completely disassembled, this figure,with the aid of the curved arrow eXpedien-ts and various center lines,showing the relationships between the various parts and disclosing eachof the parts in detail;

FIGS. 2, 3, and 4 are front elevational views showing respectively, therelationships of the moving parts existing under the followingconditions:

First, an instant slightly following the release of the locking pawl andthe beginning of a cycle of feed operation;

Second, a later stage in that cycle during which the driven member hasrotated counterclockwise approximately 20 degrees from its position inFIG. 2;

Third, the end of a cycle of driving operation; the driven memberelement in these three views is in front elevational section asindicated by the section line 4-4 of FIG. 6;

FIG. 5 is an elevational sectional view taken along the section line5--5 of FIG. 7 looking in the direction of the arrows and showing thecondition of the spiral spring when the parts are in the FIG. 4condition;

FIG. 6 is a side elevational view featuring the housing and showing theparts in the FIG. 4 condition;

FIG. 7 is a top plan view of the improved feed mechanism in accordancewith the invention, the operating conditions being as in FIG. 4;

FIGS. 8 and 9 are fragmentary and perspective views showing therelationship between certain of the feed mechanism parts and the boltrack of an automatic weapon, FIG. 8 illustrating the conditions whichprevail when the bolt is beginning its rearward travel and starting towind up the spiral spring, and FIG. 9 illustrating the conditions whichprevail when the spring has beehfully Wound and the locking pawl isabout to be released to feed another round from the magazine into thefiring chamber; and

FIG. 10 is a sectional view of a conventional rotary magazine togetherwith the driven element of the intermittent feed mechanism in accordancewith the invention.

Reference is firs-t made to FIG. 10 which shows a conventional rotarymagazine for .a machine gun. As is known to those skilled in the art, amachine gun includes a bolt which is retracted after each firingoperation. During or at the conclusion of the retraction of the bolt, arotary magazine, such as that illustrated at 65 in FIG. 10, is rotatedthrough an angle to position a new round in alignment with the firingchamber, whereupon the bolt advances and rams the new round into firingposition. It is characteristic of automatic weapons that the rotarymagazine is driven by an intermittent feed mechanism,

so controlled by the movements of the bolt that a fresh round isautomatically aligned with the firing chamber before the bolt movesforward into battery position. The rotary magazine 65 shown in FIG. 10is conventional and is provided with eight pairs of ammunition clips.

The magazine 65 is rotated step by step by the driven member 66 of anintermittent feed mechanism in accordance with the invention.

It is reiterated that the ordnance application herein shown is only oneof many potential useful applications of the novel intermittent feedmechanism. Viewing the novel intermittent feed mechanism in broadoutline, it comprises the combination of the following elements:

First, a housing 11 (FIGS. 1, 6 and 7);

Second, a driven member 66 (FIGS. 2 and 10) rotatably mounted on thehousing and formed with alternating teeth and notches angularly spacedto define steps of intermittent motion;

Third, a source of energy comprising a spiral spring 43 (FIGS. 1, 5, and7) disposed within said housing and adapted to be wound to storemechanical energy and to unwind to expend energy in driving;

Fourth, gear means 40 (FIGS. 1, 4, 8, and 9) bored for rotation andadapted to be turned in one angular direction to wind the spring(counterclockwise, FIGS. 8 and 9) and in the opposite angular directionto position the spring for rewinding;

Fifth, a locking pawl 17 (FIGS. 1, 2, and 9) pivotally mounted on saidhousing normally to engage a notch on said driven member;

Sixth, a spring-actuated stop pawl 29 (FIGS. 1 and 4) pivotally mountedon said housing and formed, and biased with a tendency to project into alater one of said notches; and

Seventh, positive actuating means 84 (FIG. 9) for releasing said lockingpawl.

This combination further includes a clutch for controlling the angularmotion of the driven member 66 in such manner as to permit the drivenmember to rotate through one step upon release of the locking pawl 17,this clutch comprising:

Eighth, a drive member 35 (FIGS. 1 and 3) rotatably mounted relative tothe housing and formed with a crank portion 36 and a shaft portion 34providing a mounting for said gear means 40;

Ninth, a driving ring member 39 (FIGS. 1 and 5) mounted on said shaftportion in concentric relation to said spring and keyed (by 47) tightly(see 46) to said drive member and loosely (see 45) to said gear means,the inner end 42 of said spring being connected to said ring member andthe outer end 54 to said gear means;

and

driven member 66, abut to force the nose of the stop pawl 29 into anotch to stop the driven member (FIG. 4). When the gear means 40 isreversed in direction-i.e., rotated from the FIG. 9 to the FIG. 8position, as by forward movement of rack 85the cam surfaces 90, 89 areseparated and the crank portion 36 is restored to its ready position(slightly clockwise from the FIG. 2 position).

The invention having been summarized briefly, the discussion proceedsfirst to a description of operation and, second, to a more detaileddescription of the structure of the intermittent feed mechanism.

In the specific embodiment shown, the driven member 66 is provided witheight teeth 67-74 (FIG. 2) and eight notches 75-82 (FIG. 3)corresponding to the eight rounds of storage capacity of the magazine65. The net result produced by the operation of the intermittent feedmechanism is to cause the driven member 66 intermittently to turncounterclockwise by an angle equal to the distance from one notch to thenext (i.e., 45). Two aspects of this intermittent motion will beconsidered, to wit: when the motion occurs, and why it occurs.

First, let attention be directed to the vertical arm 20 of the lockingpawl 17 (FIG. 2). This arm is actuated by lateral arm 19. The arm 20 andthe arm 19 of the locking pawl are in approximately right-angledrelation to each other. Near the end of the rearward travel of the bolt(not shown) a cam surface 84 on a rack 85 (FIG. 9), mounted on thebottom of the bolt and near the front thereof, strikes cam surface 83 onarm 19, depresses arm 19, and causes arm 20 to rotate clockwise asviewed in FIG. 2, whereby the lock-ing surface on arm 20 disengages fromthe notch 79 and permits the driven member 66 to be drivencounterclockwise through the FIGS. 2 and 3 positions and finally to theFIG. 4 position to cause a fresh round to be fed to the firing chamberi.e., to be aligned with the firing chamber. In the FIG. 4 position arm20 engages notch 78.

The discussion is now directed to the events which cause this rotationof the driven member 66 and the later events which cause the drivenmember to stop after rotating by one notch. For the moment it will bestated, with amplification below, that the power driving the drivenmember is driven from the spiral springs 43 (FIGS. 5 and 7). This springis convoluted in a counterclockwise direction proceeding outwardly fromits center, in such manner that it is wound up to be energized by movingits radially outer end 43 in a counterclockwise direction. The spring isrelieved when its inner end moves in a counterclockwise direction. It isreset for rewinding by moving both ends in a clockwise direction.Sufiice it for the moment to state that the rack 85 on the bolt causesthe spring to be energized during rearward movement of the bolt. Thespring relaxes when it drives the magazine. The rack on the boltfunctions in this manner because that rack has teeth 91 on its undersidewhich drive the gear 40. At the beginning of a cycle of operation therack 85 moves toward the rear of the weapon to rotate the gear 40counterclockwise to wind up the spring 43; then the new round is fed.During the chambering stroke, the rack moves forwardly to rotate thegear 40 clockwise to re-position the driving pawl for the nextoperation.

For reasons stated, therefore, the spring is energized to store powerfor driving the driven member as the bolt is retracted. Conversely, thespring is de-energized as the magazine rotates and is re-positioned asthe bolt advances toward battery position.

Let the discussion now be directed to the operations by which, as thebolt reaches its rearward position and the arm of the locking pawl 17goes into release position, the spring 43 causes the driven member 66 tobe driven counterclockwise. Mounted in concentric relation within thespring is a driving ring member 39 which is mounted on shaft 34 and isrigidly secured to the inner end 42 (FIGS. 1 and 5) of the spring.Assuming the spring 43 to be energized, its inner end 42 tends to movecounterclockwise, thus furnishing power to drive ring 39counterclockwise. The driving ring 39 is keyed by element 47 (FIGS. 1and 5) to shaft 34 and therefore tends to drive shaft 34counterclockwise. The shaft 34 is an integral portion of a drivingelement which comprises not only that shaft but also the crank 36.Pivotally mounted on the crank 36 and carried thereby is a driving pawl60 (FIGS. 1 and 3) formed with a surface which is adapted when indriving position to engage a tooth (such as 67) on the driven member 66and to drive the driven member counterclockwise.

Thus it will be seen that by reason of the power and motion traincomprising the spring 43, the driving ring 39, the shaft 34 keyedthereto, the crank 36, and the driving pawl 60, the driven member is,when released by the locking pawl 17, driven counterclockwise. Thedriving pawl 60 is normally biased outwardly into tooth-engagingposition by a hairpin biasing spring 62 (FIG. 3).

The discussion now proceeds to the sequence of events which causes thedriven member 66 to stop when it has turned angularly through one notch.In pivotally mounted relation to housing 11 is a stop pawl 29 (FIG. 4),the nose of which is formed with a stopping surface 88. The stop pawl issuitably biased so that the stopping surface tends at all times to moveinto a notch, thereby stopping the driving member 66. However, the biasprovided by the spring 58 and the formation of the stopping surface 88are such that the angular movement of the tooth (see FIG. 3, tooth 69)overrides the action of the stop pawl, unless the stop pawl is suitablydriven into stopping position by means more rigid than a spring. To thisend the crank 36 is formed at its leading edge with a cam surface 90,and the stop pawl 29 is formed at its trailing edge with a cooperatingcam surface 89 (FIG. 2) so constructed and arranged that these two camsurfaces abut each other to force the stop pawl into stopping positionafter the driven member 66 has been driven angularly by one notch. Thisstate of affairs is illustrated in FIG. 4, the two last-mentioned camsurfaces 89-90 being in abutment with each other so that the stop pawlis forced into a notch (such as 77), stopping the driven member 66,whereupon the lock pawl drops into a preceding notch (such as 78).

Attention is now directed to the return of the driving mechanism to itsready position, driving positions and ready positions beingcharacteristic of intermittent feeds.

During the forward motion of the bolt the rack on the underside of thebolt turns the gear 40 clockwise, and the spring winder 53 (FIG. 1)moves the outer end 54 of the spring 43 clockwise. The spring 43 acts asa coupling between the gear 40 and the ring 39, driving the latterclockwise. The ring 39, being keyed to shaft 34, drives that shaft andthe crank 35 clockwise, disengaging the crank cam surface from the stoppawl cam surface 89 and resulting in this set of conditions: first, thespring 43 is in unwound and de-energized condition; second, the drivingsurface of the driving pawl has underridden and then snapped behind atooth (such as 74) and is now in position to drive that tooth. It willbe understood that both the stop pawl 29 and locking pawl 17 are both inengagement with notches (such as 77 and 78 of FIG. 4) before thisspring-repositioning action occurs, and remain in such engagement duringspring repositioning.

Further structural aspects are now described.

The housing, generally indicated at 11 (FIG. 1) is suitably formed todefine a compartment in which certain of the parts, such as spring 43and the major portion of gear 40, are mounted. The housing is ofgenerally box-like configuration, formed with an open top and wings 12and 13, suitably apertured as shown at 14 to receive screws for securingthe housing in placeas, for example, on the underside of a gun. Thehousing is formed with integral upstanding lugs 15 and 16 between whichis pivotally mounted the locking pawl 17, the lugs being apertured as at18 to receive a shaft 21 to which both arms 19 and 20 of the lockingpawl 17 are secured, as by pins 22 and 23. v

The housing is tapped at 24 to receive a guide screw 25 for acompression spring 26 which presses against surface 92 and normallybiases the locking pawl 17 into locking position.

The housing is tapped at 27 to receive the screw, threaded end of a stubshaft member 28 on which is pivotally mounted the stop pawl 29, suitableretainer means (not shown) being provided to maintain this relationship.

The housing is formed with aligned bosses 30 at the rear and 31 at thefront, suitably bored to receive a rear bushing 32 and a front bushing33. Rotatably mounted within these bushings and bores is the shaftportion 34 of the driving member 35. The rear face of the crank 36 isoutboard of and parallels the front face of the housing, and the shaft34 projects through bushing 33, bushing 32, and rear washer 37, therelationship of these parts being secured by a suitable locking means(not shown), such as a retainer embracing groove 38 formed on the rearof the driving member.

Mounted with their axes in alignment with bosses 30 and 31, betweenthese bosses and in concentric relation to shaft 34, are the drivingring member 39 and the bore of the gear member 40. The driving ring 39is formed with a curled transverse notch 41 which is rigidly secured tothe curled inner end 42 of the spiral spring 43, the spring beinglocated concentrically radially outwardly of the driving ring member 39.The gear 40 is formed with an angularly long keyway 45, and driving ring39 and shaft 34 are formed with angularly short keyways 44 and 46,respectively, these three members 40, 39, and 34 being keyed together bya key 47.

. The face of gear 40 is tapped as at 49 and 50 to receive the fasteningscrews 51 and 52 of a wind-up device 53, which is rigidly secured to thegear and which simply comprises a pair of projections through which'theouter end 54 of the spring 43 is passed, the projection 55 providinga-post to which said outer end is rigidly secured.

The housing is tapped at 56 to provide a mounting for a post 57 to whichis secured the biasing spring 58 for the stop pawl, thefunction of saidbiasing spring being to urge the stop pawl normally into its stoppingposition.

Let there be considered at this point the elements mounted on the faceof the crank 36 (FIGS. 1 and 3), The projection or post 59 provides astop definitive of the driving position of driving pawl 60 which ispivotally mounted on a stub shaft 61, the latter being grooved toreceive a retainer (not shown). The driving pawl is normally urged intoa driving position by a biasing spring 62 secured to a post 63. .Crank36 is bore to interfit tightly with frontal extension 64 on the shaftportion 34 of the driving member.

Now, with further reference to FIG. 1, while the members 39, 35, and 47always rotate together as a group, the gear 40 has more than 45 ofrotational freedom with respect to this group. In practice I prefer thatthe keyway 45 approximate 55 in angular length, to provide for thisfreedom. Inspection of FIG. 1 will indicate why this freedom isprovided. Bearing in mind that, when the gear 40 has completed springwinding and has attained its counterclockwise positional limit, it is atthis phase that the locking pawl 17 is released, permitting the drivingring 39 and the driving member 35 to rotate counterclockwiseapproximately 45, while the gear 40 stands still. In other words, thekey 47 and the keyway 44 of the driving ring 39 turn 45 from the regionof shoulder 93 (FIG. 1) to the region of shoulder 48, so that at the endof the driving or intermittent feed operation key 47 is at or nearshoulder. 48. When the gear 40 is turned clockwise during return of theparts to the ready position, shoulder 48 impacts against key 47, drivingring 39 and the driving member 35 clockwise. At the beginning of thenext cycle of operation, the gear 40 is turned counterclockwise to windup spring 43, while the driving ring 39 stands still, whereby shoulder93 moves counterclockwise so that key 47 is effectively restored to aposition closely adjacent shoulder 93. The point of this detail is thatduring spring winding the driving ring 39 stands still, while gear 40moves counterclockwise. During the feeding operation proper the gear 40stands still, while the driving ring 39 moves counterclockwise. Duringthe return operation, both the gear 40 and the driving ring 39 moveclockwise together.

Thus it will be seen that, in accordance with the invention, there hasbeen provided an improved intermittent motion mechanism comprising, incombination:

First, a rotatably mounted driven member 66 formed (by 67-82) to definemotion steps.

Second, rotary means 39, 35, and 60 for driving the driven member.

Third, a spiral spring 43 for supplying the power to drive the rotarymeans.

Fourth, spring-winding means 40, 53 movable in the counterclockwisedirection to wind the spring by displacing end 54 of the spring Whilethe other end 42 is restrained at 41 by the rotary driving means.

Fifth, locking means 17 normally engaging said driven member andrestraining said rotary means and said spring, said locking means beingdisengaged from said driven member after the spring is wound, wherebythe spring drives-said rotary means, said spring-winding and rotarymeans being mounted with sufficient angular freedom (key 47 moving from93 to 48) to permit such relative motion.

Sixth, stop means 29 for engaging the driven member to terminate amotion step.

The spring-winding means 40, 53 is movable clockwise in synchronism withthe rotary means 39, 35, 60 in order to reposition the spring.

While there has been shown and described What is at present consideredto be the preferred embodiment of the invention, it will be obvious tothose skilled in the art that various modifications and changes may bemade therein without departing from the true scope of the invention asdefined by the appended claims.

I claim:

1. An intermittent feed mechanism which comprises, in combination:

9 a housing;

a driven member rotatably mounted on said housing and formed withalternating teeth and notches angularly spaced to define steps ofintermittent motion;

a source of energy comprising a spiral spring disposed within saidhousing and adapted to be wound to store mechanism energy and to unwindto expend driving power;

gear means bored for rotation and adapted to be turned in oneangulardirection to wind said spring and in the opposite angular direction toposition the spring for rewinding;

a locking pawl pivotally mounted on said housing normally to engage anotch on said driven member;

a spring-actuated stop pawl pivotally mounted on said housing and formedand biased with a tendency to project into a later one of said notches;

and a clutch for controlling the angular motion of said drivenmember,said clutch comprising:

a drive member rotatably mounted relative to said housing and formedwith a crank portion and a shaft portion, said shaft portion providing amounting for said gear means;

a driving ring member keyed tightly to said drive member and loosely tosaid gear means to permit limited angular displacement between the ringmember and gear means when the spring is wound or unwound, the inner endof said springbeing connected to said ring member and the outer end tosaid gear means;

and a spring-actuated driving pawl pivotally mounted on said crankportion and adapted normally to engage one of said teeth to drive thedriven member.

2. An intermittent feed mechanism in accordance with claim 1, andpositive actuating means for releasing said locking pawl.

3. An intermittent feed mechanism in accordance with claim 1 in whichsaid crank portion and said stop pawl are formed with cam surfaceswhich, on completion of a step of motion of the driven member, abut toforce the stop pawl into a still later one of said notches to stop thedriven member.

4. An intermittent feed mechanism in accordance with claim 3, andpositive actuating means for releasing said locking pawl.

5. An intermittent feed mechanism in accordance with claim 4 in whichthe driven member drives a rotary magazine of an automatic weapon, andin which the positive actuating means is secured to the bolt of saidautomatic weapon.

6. In an intermittent feed mechanism for the magazine of an automaticweapon, the combination of:

a rotatably mounted driven member formed to define motion steps;

rotary means having a crank portion for driving the driven member;

a spiral spring for supplying the power to drive said rotary means;

spring-winding means independent of the driven member and movable in oneangular direction to wind said spring by displacing the outer end of thespring while the inner end is restrained by the rotary driving means;

the spring-winding means comprising a gear mounted coaxially with saidrotary driving means; locking means normally engaging said driven memberand restraining said rotary means and said spring,

said locking means being disengaged from said driven member after thespring is wound, whereby the spring drives said rotary means;

means for keying said spring-winding and rotary driving means withsuflicient angular freedom to permit relative motion between thespring-winding means and the rotary driving means;

and stop means for engaging the driven member to terminate a motionstep;

the spring-winding means being movable in the opposite angular directionin synchronism with the rotary means for resetting the spring.

7. In an intermittent feed mechanism for the magazine of an automaticweapon, the combination of:

a rotatably mounted driven member formed to define motion steps;

rotary means having a crank portion for driving the driven member;

a spiral spring for supplying the power to drive said rotary means;

spring-winding means independent of the driven member and movable in oneangular direction to wind said spring by displacing the outer end of thespring while the inner end is restrained by the rotary driving means;

the spring-winding means comprising a gear mounted coaxially with saidrotary driving means; locking means normally engaging said driven memberand restraining said rotary means and said spring,

said locking means being disengaged from said driven member after thespring is wound, whereby the spring drives said rotary means;

means for keying said spring-winding and rotary driving means withsufiicient angular freedom to permit relative motion between the springwinding means and the rotary driving means;

and stop means for engaging the driven member to terminate a motionstep;

said rotary driving means and said stop means being so formed andarranged as to position said stop means for such engagement;

the spring-winding means being movable in the opposite angular directionin synchronism with the rotary means for resetting the spring.

8. In an intermittent feed mechanism for the quick starting and stoppingof a rotary magazine for an automatic weapon, the combination of:

a rotatably mounted driven member formed to define motion steps;

locking means normally engaging said driven member but releasable toermit driving of said driven member at a high-torque level;

resettable rotary driving means for driving the driven member; androtatably mounted stopping means for terminating a motion step of thedriven member;

said rotary driving means and said stopping means being so formed andarranged that the driving means directly cams and turn the stoppingmeans into engagement with the driven member to arrest the motion ofsaid high inertia load.

9. In an intermittent feed mechanism, the combination in accordance withclaim 8 in which the driven member is formed as a circular ratchet, thedriving means includes a crank portion, and the locking means andstopping means are formed as outer and inner pawls, respectively.

10. The combination is accordance with claim 9 and spring means forsupplying torque to the rotary driving means.

11. The combination in accordance with claim 10 and rotatably mountedgear means for building up the torque level of the torque supplyingmeans.

12. The combination in accordance with claim 11 in which the gear meansis rotatable in one direction to build up such torque and in the reversedirection to reset the driving means, but does not move when the drivenmember is being driven.

13. The combination in accordance with claim 12 in which the rotarydriving means comprises a crank portion and a pivotally mounted drivingpawl.

14. The combination in accordance with claim 13 in which both thedriving and stopping pawls are normally biased toward their activepositions, the driving pawl being overridden when the driving means isreset, and the stop pawl being overridden when the driven member isdriven.

15. An intermittent feed mechanism having spring-wind, spring rewind,and reset conditions of operation which comprises, in combination:

a supporting framework;

driven means rotatably mounted with reference to said framework andformed with discontinuities definitive of steps of intermittent motion;

a mechanically strainable spring;

gear means bored for rotation and adapted to be turned in one angulardirection to strain the spring during the spring-wind operation and inthe opposite direction to position the spring for rewinding during thereset operation;

locking means pivotally secured with reference to said frameworknormally to engage one of said discontinuities to hold the driven meansstationary during spring-wind and spring-reset operation, said lockingmeans being disengaged to permit the spring t unwind;

stopping means pivotally ecured with reference to said framework;

and a clutch for controlling the angular motion of said driven means,said clutch comprising:

rotatably mounted drive means driven by said spring and formed with ashaft portion providing a mounting for the gear means, said drive meansand gear means being so keyed together as to provide for synchronousangular motion during the spring-positioning operation, but [for limitedrelative rotational freedom during the spring-wind and spring-unwindoperations, the drive means being provided with a surface which engagesone of said discontinuities to drive the driven means during thespring-unwind operation. 16. In an intermittent feed mechanism for arotary magazine for an automatic weapon, the combination of:

a rotary driven member, a stop pawl,

and rotary driving means including a crank member and n a driving pawl,said stop pawl being rotatably mounted on said crank member,

said crank member and stop pawl being formed with surfaces which abut atthe conclusion of a step of intermittent motion, whereby the crankmember directly turns and forces the stop pawl into position to stop thedriven member.

17. In an intermittent feed mechanism of the type including a spiralspring having inner and outer ends, the combination of:

rotatable winding means for moving the outer end of the spring to windit, said winding means being formed with a relatively long keyway havingtwo shoulders;

a driving ring secured to the inner end of said spring and formed with arelatively short keyway;

a key tightly fitted to the short keyway and loosely fitted to the longkeyway;

and releasable means for restraining said driving ring when the windingmeans turns in the angular direction to wind the spring;

the releasable means being opened to permit the driving ring to rotaterelative to the winding means and to relieve the spring, so that the keymoves to a position adjacent one of said shoulders,

said one shoulder abutting against the key to move the driving ringbackW-ardly in synchronism with the winding means when the winding meansturns in the opposite angular direction to reset the spring and drivingring,

the other shoulder finally abutting against the key when the windingmeans again turns in the first-mentioned -10 angular direction to rewindthe spring while the releasable means again restrains the driving ring.

18. In an intermittent feed mechanism, the combination of:

turnable winding means;

turnable driving means;

means for loosely coupling the driving and winding means to permitlimited slack therebetween;

a source of torque between the winding and driving means;

and releasable locking means for restraining the driving means while thewinding means is turned in one direction to energize said source;

the releasable locking means being released to permit the source oftorque to drive the driving means onwardly in said one direction whilethe winding means in stationary, whereby said slack is taken up in onedirection;

the winding means and driving means being turnable in synchronism in theopposite direction to reset said source and to re-position said drivingmeans;

the releasable locking means again restraining the driving means whenthe winding means in again turned in the first-mentioned direction toenergize said source while slack is taken up in the opposite direction.

19. In an intermittent feed mechanism, the combination in accordancewith claim 18 in which the turnable driving means drives a drivenmember,

in which the releasable locking means is a locking pawl engageable withthe driven member,

in which there is mounted on the driven member a driving pawl engageablewith the driven member,

and in which a stop pawl terminates each step of intermittent motion ofthe driven member.

References Cited by the Examiner UNITED STATES PATENTS 2/59 Olson 74-8225/61 Dixon 89-33 FOREIGN PATENTS 954,477 12/49 France.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,204,528 September 7, 1965 Kenneth J. J. McGowan I It is herebycertified that error appears in the above numbered patent requiringcorrection and that the said Letters Patent should read as correctedbelow.

Column 3, line 44, for "driven", second occurrence, read derived sameline 44, for "springs" read spring line 48, for "43" read 54 column 4,line 55, for "35" read 36 column 10, line 23, for "in", firstoccurrence, read is Signed and sealed this 29th day of March 1966.

(SEAL) Attest:

ERNEST W. SWIDER Attesting Officer EDWARD J. BRENNER Commissioner ofPatents

1. AN INTERMITTENT FEED MECHANISM WHICH COMPRISES, IN COMBINATION: AHOUSING; A DRIVEN MEMBER ROTATABLY MOUNTED ON SAID HOUSING AND FORMEDWITH ALTERNATING TEETH AND NOTCHES ANGULARLY SPACED TO DEFINE STEPS OFINTERMITTENT MOTION; A SOURCE OF ENERGY COMPRISING A SPIRAL SPRINGDISPOSED WITHIN SAID HOUSING AND ADAPTED TO BE WOUND TO STORE MECHANISMENERGY AND TO UNWIND TO EXPEND DRIVING POWER; GEAR MEANS BORED FORROTATION AND ADAPTED TO BE TURNED IN ONE ANGULAR DIRECTION TO WIND SAIDSPRING AND IN THE OPPOSITE ANGULAR DIRECTION TO POSITION THE SPRING FORREWINDING; A LOCKING PAWL PIVOTALLY MOUNTED ON SAID HOUSING NORMALLY TOENGAGE A NOTCH ON SAID DRIVEN MEMBER; A SPRING-ACTUATED STOP PAWLPIVOTALLY MOUNTED ON SAID HOUSING AND FORMED AND BIASED WITH A TENDENCYTO PROJECT INTO A LATER ONE OF SAID NOTCHES; AND A CLUTCH FORCONTROLLING THE ANGULAR MOTION OF SAID DRIVEN MEMBER, SAID CLUTCHCOMPRISING: A DRIVE MEMBER ROTATABLY MOUNTED RELATIVE TO SAID HOUSINGAND FORMED WITH A CRANK PORTION AND A SHAFT PORTION, SAID SHAFT PORTIONPROVIDING A MOUNTING FOR SAID GEAR MEANS; A DRIVING RING MEMBER KEYEDTIGHTLY TO SAID DRIVE MEMBER AND LOOSELY TO SAID GEAR MEANS TO PERMITLIMITED ANGULAR DISPLACEMENT BETWEEN THE RING MEMBER AND GEAR MEANS WHENTHE SPRING IS WOUND OR UNWOUND, THE INNER END OF SAID SPRING BEINGCONNECTED TO SAID RING MEMBER AND THE OUTER END TO SAID GEAR MEANS; ANDA SPRING-ACTUATED DRIVING PAWL PIVOTALLY MOUNTED ON SAID CRANK PORTIONAND ADAPTED NORMALLY TO ENGAGE ONE OF SAID TEETH TO DRIVE THE DRIVENMEMBER.